My blogs have three columns, with the center carrying the articles and being the widest.

Part of the reason I wanted the graphic headers (to use like a spacer) was to solve a problem in Safari, which showed a wide left column and a narrower than expected center column on search results pages. In other words, it didn't fit the look and feel of the structural format of the blog -- and it looked bad. Firefox for Mac didn't show this. Explorer and Firefox on WIndows didn't have the aesthetics problem either.

To get what I wanted for a visual result, I went into the styles template for the MAIN PAGE and changed the following CSS code (the change? left col: "width: 15%" to "width: 215px"; right col: "width: 20%" to "width: 195px"):

Strangely this degraded the look in WIndows (Explorer and Firefox) very slightly -- narrowing the center column a little and bringing the right column toward the left a little. Overall, the net effect is better visual with the fixed column widths.